CN117151130A

CN117151130A - Method, apparatus, communication device and readable storage medium for transmitting back scattering signal

Info

Publication number: CN117151130A
Application number: CN202210571731.6A
Authority: CN
Inventors: 吴凯; 蔡建生; 王勇; 顾一
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2022-05-24
Filing date: 2022-05-24
Publication date: 2023-12-01
Also published as: WO2023226844A1

Abstract

The application discloses a method, a device, a communication device and a readable storage medium for transmitting a back scattering signal, wherein the method comprises the following steps: the tag determines parameters related to the transmission of the backscatter signal according to the first information; wherein the first information includes at least one of: a first identifier, wherein the first identifier comprises an identifier of the tag or a temporary identifier of the tag; a first value indicating a random number generated by the tag; a second value for indicating a counter value of the tag; a third value for indicating a step size of a counter of the tag; a group identification or an intra-group identification of the tag; session number or process number; information received from the reader/writer.

Description

Method, apparatus, communication device and readable storage medium for transmitting back scattering signal

Technical Field

The application belongs to the technical field of communication, and particularly relates to a method and a device for transmitting a back scattering signal, communication equipment and a readable storage medium.

Background

In current backscatter communication systems, a tag is used to backscatter an incoming carrier signal for signal transmission. Due to the large number of tags (tags), the tags perform information transmission by back-scattered signals at a randomly determined point in time. When a large number of tags exist, the different tags may transmit the backscatter signal at the same time, and at this time, the performance of the reader-writer for receiving the backscatter signal may be degraded due to the collision between the backscatter signals.

Disclosure of Invention

The embodiment of the application provides a method, a device, communication equipment and a readable storage medium for transmitting a back scattering signal, which solve the problem that the performance of a reader-writer for receiving the back scattering signal is reduced due to the conflict between the back scattering signals.

In a first aspect, a method for transmitting a backscatter signal is provided, comprising:

the tag determines parameters related to the transmission of the backscatter signal according to the first information;

wherein the first information includes at least one of:

a first identifier, wherein the first identifier comprises an identifier of the tag or a temporary identifier of the tag;

a first value indicating a random number generated by the tag;

a second value for indicating a counter value of the tag;

a third value for indicating a step size of a counter of the tag;

a group identification or an intra-group identification of the tag;

session number or process number;

information received from the reader/writer.

In a second aspect, a method for transmitting a backscatter signal is provided, comprising:

the reader-writer determines parameters related to the transmission of the back scattering signals according to the first information;

the reader detects the backscatter signal according to the parameter;

Wherein the first information includes at least one of:

a first identifier, wherein the first identifier comprises an identifier of a tag or a temporary identifier of the tag;

a first value indicating a random number generated by the tag;

a second value for indicating a counter value of the tag;

a third value for indicating a step size of a counter of the tag;

a group identification or an intra-group identification of the tag;

session number or process number;

information received from the reader/writer.

In a third aspect, there is provided a backscatter signal transmission device for use with a tag, the device comprising:

a first determining module for determining a parameter related to the transmission of the backscatter signal based on the first information;

wherein the first information includes at least one of:

a first value indicating a random number generated by the tag;

a second value for indicating a counter value of the tag;

a third value for indicating a step size of a counter of the tag;

A group identification or an intra-group identification of the tag;

session number or process number;

information received from the reader/writer.

In a fourth aspect, there is provided a backscatter signal transmission device for use with a reader/writer, the device comprising:

a third determining module for determining parameters related to the transmission of the backscatter signal based on the first information;

the detection module is used for detecting the back scattering signal according to the parameters;

a first value indicating a random number generated by the tag;

a second value for indicating a counter value of the tag;

a third value for indicating a step size of a counter of the tag;

a group identification or an intra-group identification of the tag;

session number or process number;

information received from the reader/writer.

In a fifth aspect, there is provided a communication device comprising: a processor, a memory and a program or instruction stored on the memory and executable on the processor, which when executed by the processor, implements the steps of the method according to the first or second aspect.

In a sixth aspect, there is provided a readable storage medium having stored thereon a program or instructions which when executed by a processor implement the steps of the method according to the first or second aspect.

In a seventh aspect, there is provided a chip comprising a processor and a communication interface coupled to the processor for running a program or instructions implementing the steps of the method according to the first or second aspect.

In an eighth aspect, there is provided a computer program/program product stored in a non-transitory storage medium, the program/program product being executed by at least one processor to implement the steps of the method as described in the first or second aspect.

A ninth aspect provides a communication system comprising a terminal for performing the steps of the method according to the first aspect and a network side device for performing the steps of the method according to the second aspect.

In the embodiment of the application, the tag determines the parameters related to the transmission of the backscatter signal according to the first information, and because the content contained in the first information is related to the tag itself or the content contained in the first information is a non-fixed value, the tags can generate different parameters based on different first information, so that the tags can transmit the backscatter signal by adopting different parameters at the same time, and further the reader can detect the backscatter signals of the tags at the same time, thus supporting the backscatter transmission of the tags at the same time, and improving the efficiency of completing the backscatter communication between the reader and the tags under the condition of a plurality of tags.

Drawings

FIG. 1 is one of the schematic diagrams of backscatter communications;

FIG. 2 is a second schematic diagram of backscatter communications;

FIG. 3 is a schematic diagram of information transfer between a reader and a Tag;

FIG. 4 is a schematic diagram of a Backscatter application scenario;

FIGS. 5a, 5b and 5c are schematic diagrams of another backscattering application scenario;

FIG. 6 is a flowchart of a method for transmitting a backscatter signal according to an embodiment of the present application;

FIG. 7 is a second flowchart of a method for transmitting a backscatter signal according to an embodiment of the present application;

FIG. 8 is a schematic diagram of Miller subcarrier modulation provided in an embodiment of the application;

FIG. 9 is a schematic diagram of the frequency components of a backscatter signal provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of a backscatter signal transmission device according to an embodiment of the present application;

FIG. 11 is a schematic diagram of a back-scattered signal transmission device according to a second embodiment of the present application;

fig. 12 is a schematic diagram of a communication device according to an embodiment of the present application.

Detailed Description

The technical solutions of the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the application, fall within the scope of protection of the application.

The terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application are capable of operation in sequences other than those illustrated or otherwise described herein, and that the "first" and "second" distinguishing between objects generally are not limited in number to the extent that the first object may, for example, be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/" generally means a relationship in which the associated object is an "or" before and after.

It should be noted that the techniques described in the embodiments of the present application are not limited to long term evolution (Long Term Evolution, LTE)/LTE evolution (LTE-Advanced, LTE-a) systems, but may also be used in other wireless communication systems, such as code division multiple access (Code Division Multiple Access, CDMA), time division multiple access (Time Division Multiple Access, TDMA), frequency division multiple access (Frequency Division Multiple Access, FDMA), orthogonal frequency division multiple access (Orthogonal Frequency Division Multiple Access, OFDMA), single carrier frequency division multiple access (Single-carrier Frequency Division Multiple Access, SC-FDMA), and other systems. The terms "system" and "network" in embodiments of the application are often used interchangeably, and the techniques described may be used for both the above-mentioned systems and radio technologies, as well as other systems and radio technologies. The following description A New air interface (NR) system is described for purposes of illustration and NR terminology is used in much of the description below, but the techniques are also applicable to applications other than NR system applications, such as generation 6 (6 ^th Generation, 6G) communication system.

In order to facilitate understanding of the embodiments of the present application, the following technical points are first described:

1. regarding backscatter communications (Backscatter Communication, BSC):

backscatter communication refers to the transmission of its own information by signal modulation of radio frequency signals in other devices or environments by a backscatter communication device.

A backscatter communications device may include:

(1) The backscatter communication device in conventional radio frequency identification (Radio Frequency Identification, RFID), typically a Tag, belongs to a Passive internet of things (Internet of Things, ioT) device (otherwise known as a Passive-IoT).

(2) Semi-passive (semi-passive) tags, the downstream receiving or upstream reflecting of such tags has a certain amplifying capability;

(3) Tags with active transmission capability (or active Tags) can transmit information to a reader (e.g., reader) independent of reflection of an incoming signal.

The reader-writer, namely the radio frequency tag reader-writer, is one of two important components (tag and reader-writer) of the radio frequency identification system. The radio frequency tag read-write device has other popular names according to specific implementation functions, such as: reader (Reader), interrogator (Communicator), scanner (Scanner), reader (Reader and Writer), programmer (Programmer), reading Device (Reading Device), portable Reader (Portable Readout Device), automatic Device identification equipment (Automatic Equipment Identification Device, AEI), etc.

As shown in fig. 1, two links (links) are included between the reader and the tag, link 1 is a link from the reader to the tag, and link 2 is a link from the tag to the reader.

A simple implementation is that when a Tag needs to send a '1', the Tag reflects the incoming carrier signal and when the Tag needs to send a '0', it does not.

The backscatter communication device controls the reflection coefficient Γ of the circuit by adjusting its internal impedance, thereby changing the amplitude, frequency, phase, etc. of the incident signal, effecting modulation of the signal. Wherein the reflection coefficient of the signal can be characterized as:

wherein Z is ₀ For the characteristic impedance of the antenna, Z ₁ Is the load impedance. Let the incident signal be S _in (t) the output signal isThus, by reasonably controlling the reflection coefficient, a corresponding amplitude modulation, frequency modulation or phase modulation can be achieved, as shown in fig. 2.

2. Regarding information transfer between the reader and Tag, as shown in fig. 3.

The instructions of the reader are shown in table 1.

Table 1: instructions of the reader.

The Tag status is shown in table 2.

Table 2: the state of the Tag label.

The existing protocol design of ultra-high frequency (Ultra High Frequency, UHF) RFID requires a reader to send a Query instruction (Query) and then a Tag response (Reply) in the checking mode, namely, a 16-bit random number is generated for the reader. And then the reader sends the sequence to the Tag through an ACK instruction, and the Tag sends related data to the reader.

3. Application scenarios relating to backscatter

Scene 1: cell backscatter scenario-without terminal assistance (Scenarios for cellular backscatter-w/o UE assisted), as shown in fig. 4.

Scene 2: terminal assisted cellular backscatter scenario (Scenarios for cellular backscatter with UE assisted), as shown in fig. 5a, 5b and 5c, the terminal receives feedback information sent by the tag in fig. 5 a. In fig. 5b, the terminal sends a Control Word (CW) or control signaling to the Tag; wherein the control signaling type includes at least one of: select, input, access. The network device (e.g., base station) receives the feedback information of the Tag. In fig. 5c, the terminal transmits a carrier wave and receives a backscatter signal of a Tag, and after receiving the backscatter signal of the Tag, the terminal forwards the collected information to a network device (e.g. a base station).

4. Competitive communication procedure in relation to backscatter communication systems

In existing backscatter communication systems, a reader-writer typically receives only one Tag's backscatter signal at a time. For example, in the RFID inventory process, when the reader sends a control command to start the inventory process, a value Q is indicated. Tag randomly selects a value q among the values that locally generate a {0, …,2^Q-1 }. The Tag with the current random value of 0 responds to the control command of the reader-writer to transmit the backscatter signal. The transmission of the backscatter signal is temporarily not performed by the Tag whose current random value is not 0. After completing communication with a Tag having a random value of 0, the reader/writer may continue to transmit a control command (e.g., queryRep) indicating, for example, that the Tag subtracted by 1 from the generated random number, and the Tag having a random value subtracted by 0 performs backscatter transmission in response to the control command.

The above procedure belongs to a random multiple access procedure, and there is a possibility that no Tag is back-scattered, for example, the current random number of no Tag is 0. There is also a possibility that multiple tags locally generate the same random number, which results in a possibility that multiple tags simultaneously perform backscatter transmission at a certain moment, in which case the reader-writer cannot detect any backscatter signal of the tags with a high probability, and does not receive feedback of the backscatter signal to the tags. In this case, the tags will continue to receive the control commands from the reader/writer, waiting for a new opportunity for backscatter transmission. Therefore, when the reader-writer sends a control command, a reasonable Q value is selected, and the Q value can be gradually adjusted in the checking process so as to reduce the collision probability in the communication process with a plurality of tags. This of course also means that the time to complete a communication with multiple tags is prolonged.

In the existing scheme, if the parameters of the backscattering signal transmission of a plurality of tags at the same time are the same, the reader-writer side cannot detect the backscattering signals of the plurality of tags at the same time, and the efficiency of completing the backscattering communication of the plurality of tags is negatively affected.

The embodiments of the present application provide a method, an apparatus, a communication device, and a readable storage medium for transmitting a backscatter signal, which are described in detail below with reference to the accompanying drawings.

Referring to fig. 6, an embodiment of the present application provides a method for transmitting a backscatter signal, applied to a tag, including the following specific steps: step 601.

Step 601: the tag determines parameters related to the transmission of the backscatter signal according to the first information;

wherein the first information includes at least one of:

(1) A first identifier, wherein the first identifier comprises an identifier of the tag or a temporary identifier of the tag;

for example, the label is identified as a, and the temporary label of the label is identified as B.

Taking the temporary Identifier (ID) with the first identifier as a tag as an example, the tag id#0 uses the parameter 0, the tag id#1 uses the parameters 1, …, and the tag id#m uses the parameter M to perform backscatter transmission, 0= < M < = M-1. The tag may perform a preset operation according to the ID value, and determine a parameter of the backscatter signal, for example, if mod (ID, M) =m, the parameter M is used to perform transmission of the backscatter signal, where M is indicated by the reader or predefined.

(2) A first value indicating a random number generated by the tag;

for example, the tag generates a random number of C.

(3) A second value for indicating a counter value of the tag;

for example, the counter value generated by the tag is D, and the initial value of the counter of the tag may be a random number generated by the tag.

Tags with current counter values of 0,1 and … M-1 can transmit back scattering signals at the same time, and tags with different counter values use different parameters for back scattering transmission. Tag 0 uses parameter 0, tag 1 uses parameters 1, …, tag M uses parameter M for transmission of the backscatter signal, 0= < M < = M-1, M being indicated by the reader or predefined.

(4) A third value for indicating a step size of a counter of the tag;

for example, the step size of the counter generated by the tag is E.

(5) A group Identification (ID) or an intra-group identification of the tag;

thus, the tag may be backscatter signaled in a packet mode, and the tag may include a group identification and an intra-group identification.

(6) Session number (session number) or process number (process number);

in this way, the reader/writer can perform backscatter communication with multiple tags using multiple sessions or processes.

(7) Information received from the reader/writer.

For example, the reader/writer instructs the tag to transmit the backscatter signal at a particular frequency, and it is understood that the specific content of the information instructed by the reader is not limited.

In the embodiment of the application, the content contained in the first information for generating the parameters related to the transmission of the back-scattered signal by the tag is related to the tag itself or the content contained in the first information is a non-fixed value, so that a plurality of tags can respectively generate different parameters based on different first information, and the plurality of tags can transmit the back-scattered signal by adopting different parameters at the same time.

In one embodiment of the present application, the parameter related to the transmission of the backscatter signal is used to indicate the frequency information of the transmission of the backscatter signal by the tag, so that it is ensured that a plurality of tags perform the parameter of the backscatter signal in a frequency division multiplexing manner.

Optionally, the parameter includes at least one of:

(1) A first parameter indicative of transmission of a backscatter signal;

for example, the first parameter is 1-bit indication information, and the value of the 1-bit indication information is "1", which indicates that transmission of the backscatter signal is performed.

(2) A second parameter indicating that transmission of the backscatter signal is not to be performed;

for example, the first parameter is 1 bit of indication information, and the value of the 1 bit of indication information is "0" to indicate that no transmission of the backscatter signal is performed.

(3) A third parameter indicative of a frequency of the backscattered signal;

for example, tag 0 transmits a backscatter signal at frequency 0 and tag 1 transmits a backscatter signal at frequency 1; tag 2 transmits the backscatter signal at frequency 2 so that multiple tags can transmit backscatter signals at different frequencies at the same time, reducing collisions by frequency division multiplexing the transmission of the backscatter signal.

Optionally, the third parameter is a first frequency offset value, where the first frequency offset value is used to indicate a frequency offset value relative to an incident carrier frequency, and the incident carrier frequency or the first frequency offset value may be predefined or indicated by a reader/writer.

(4) A subcarrier (subcarrier) frequency of the backscattered signal;

subcarriers may also be described herein as subcarriers.

For example, tag 0 performs transmission of a backscatter signal on subcarrier 0; tag 1 performs transmission of a backscatter signal on subcarrier 1; tag 2 performs transmission of the backscatter signal on subcarrier 2 so that multiple tags can perform backscatter transmission on different subcarriers at the same time.

Alternatively, the subcarrier frequency of the backscattered signal may be N times or 1/N times the reference subcarrier frequency, where N is a natural number greater than 0, and the reference subcarrier frequency, the N, may be predefined or indicated by a reader/writer.

(5) A first duration or a first level switching period of the backscatter signal.

For example, the first duration or the first level switching period of the transmission of the backscatter signal by the tag 0 is X, the first duration or the first level switching period of the transmission of the backscatter signal by the tag 1 is Y, and the first duration or the first level switching period of the transmission of the backscatter signal by the tag 2 is Z, wherein X, Y, Z are different, and thus the frequency of the backscatter signal is different, so that a plurality of tags can perform the transmission of the backscatter at the same time with different first durations or first level switching periods, thereby avoiding collision.

Optionally, the first duration is K times or 1/K times the reference level duration, where K is a natural number greater than 0, and the reference level duration and K may be predefined or indicated by the reader.

In one embodiment of the application, the method further comprises: the tag receives second information, where the second information is used to instruct the tag to determine a parameter related to the transmission of the backscatter signal according to the first information, or the second information is used to instruct the tag to determine a parameter related to the transmission of the backscatter signal according to a specific session number or a process number.

For example, the tag receives the second information from the reader, so that the reader can explicitly instruct the tag to transmit the backscatter signal using different parameters at the same time, or the reader can directly instruct the tag to determine the parameters related to the transmission of the backscatter signal according to a specific session number or process number.

In one embodiment of the application, the tag determines a parameter of the backscatter signal based on the first information, comprising:

in case the third value is included in the first information and the third value is larger than 1, the tag determines a parameter related to the transmission of the backscatter signal from the first information.

For example, if the step size of the counter of the tag is E, and E >1, the tag determines a parameter related to the transmission of the backscatter signal from the first information. It will be appreciated that the reader may instruct the tag that in case the step E >1 of the counter of the tag, the tag may determine the parameter related to said backscatter signal transmission from the first information.

In one embodiment of the application, the method further comprises:

in the case where the counter value of the tag is any one of 0 to a fourth value, the tag performs transmission of a backscatter signal, the fourth value is equal to the third value minus 1, and the third value is greater than or equal to 1.

In this way, the tag with the counter value of 0 … … E-1 can transmit the back scattering signal at the same time, so that the transmission of the back scattering signal by no tag is avoided as much as possible, and when a plurality of tags can transmit the back scattering signal, the tags can transmit the back scattering signal through different parameters, so that the collision probability is reduced.

In one embodiment of the application, the method further comprises:

the tag receives third information indicating that the tag subtracts the counter value by the third value, e.g. the reader/writer may indicate that the tag subtracts the counter value by a step size via a control command.

In one embodiment of the application, the tag determines, based on the first information, a parameter associated with the transmission of the backscatter signal, including one of:

(1) In the case that the group identifier of the tag is a specific group identifier, the tag determines the parameter according to the group identifier of the tag;

for example, the tag determines parameters such as frequency, subcarrier frequency, first level duration/first level switching period, etc. based on the tag's intra-group identification.

(2) And in the case that the group identifier of the tag is a specific group identifier, the tag determines the parameter according to the group identifier of the tag.

For example, the tag determines parameters such as frequency, subcarrier frequency, first level duration/first level switching period, etc. based on the tag's group identification. In one embodiment of the application, the group identity or intra-group identity of the tag is determined according to one of the following: the first identifier; the first value; the second value; and information indicated by the reader-writer.

In one embodiment of the present application, the tag determines the parameter according to a group identifier or an intra-group identifier of the tag, including:

The tag determines the remainder obtained by dividing the first identifier (A or B) or the first value (C) or the second value (D) by the fifth value as the parameter;

wherein the fifth value is indicated by the reader or predefined.

That is, the tag determines the parameter from the value of m=mod (a/B/C/D, M); m is indicated by a reader or predefined, and the tag transmits a back scattering signal according to the parameter M.

In one embodiment of the application, the method further comprises:

the tag receives fourth information, the fourth information being used to indicate at least one of:

(1) Modifying the group identification of the tag;

(2) The tag of the specific group identifier transmits a back scattering signal;

(3) Modifying the intra-group identity of the tag;

(4) The tags identified within a particular group transmit backscatter signals.

In one embodiment of the present application, at least one of the first information, the second information, the third information, and the fourth information is carried in a control command sent by a reader/writer;

wherein the control command includes at least one of: selecting a command, inquiring a command, repeating the inquiring command and adjusting the inquiring command.

In one embodiment of the application, the method further comprises:

the tag transmits a backscatter signal according to a first requirement and a parameter of the backscatter signal;

wherein the first requirement comprises: when the tag uses any parameter of the back-scattered signal to transmit the back-scattered signal, if the number of transmitted bits is the same, the second duration of transmitting the same number of bits is the same.

In one embodiment of the present application, in the case where the subcarrier frequency of the backscatter signal is N times the reference subcarrier frequency, the number of level switching cycles corresponding to the subcarrier frequency of the backscatter transmission is 1/N of the number of level switching cycles corresponding to the reference subcarrier frequency in the second duration.

In one embodiment of the present application, the level switching period sequentially includes: high level and low level, or low level and high level, wherein the sum of the duration of the high level and the duration of the low level is the level switching period.

In one embodiment of the application, the information carried by the backscattered signal includes at least one of: the temporary identification of the tag, the article coding, the handle of the tag, the error coding and the data.

Referring to fig. 7, an embodiment of the present application provides a method for transmitting a backscatter signal, which is applied to a reader, and includes the following specific steps: step 701 and step 702.

Step 701: the reader-writer determines parameters related to the transmission of the back scattering signals according to the first information;

step 702: the reader detects the backscatter signal according to the parameter;

wherein the first information includes at least one of:

(2) A first value indicating a random number generated by the tag;

(3) A second value for indicating a counter value of the tag;

(4) A third value for indicating a step size of a counter of the tag;

(5) A group identification or an intra-group identification of the tag;

(6) Session number (session number) or process number (process number);

(7) Information received from the reader/writer;

in one embodiment of the application, the parameter comprises at least one of:

(1) A first parameter indicative of transmission of a backscatter signal;

(3) A third parameter indicative of a frequency of the backscattered signal;

(4) A subcarrier (subcarrier) frequency of the backscattered signal;

subcarriers may also be described herein as subcarriers.

In one embodiment of the present application, the detecting of the backscatter signal by the reader/writer according to the parameter includes:

And the reader-writer detects the back scattering signal according to the parameter in at least one bandwidth range.

In one embodiment of the present application, the third parameter is a first frequency offset value, the first frequency offset value being used to indicate a frequency offset value relative to an incident carrier frequency;

or,

the subcarrier frequency of the back-scattered signal is N times or 1/N times the reference subcarrier frequency;

or,

the first duration is K times or 1/K times the reference level duration;

wherein N, K is a natural number greater than 0.

In one embodiment of the application, one or more of the incident carrier frequency, the reference subcarrier frequency, the reference level duration, the first frequency offset value, the N and the K are predefined or determined by the reader/writer.

In one embodiment of the application, the method further comprises:

the reader-writer sends second information, the second information is used for indicating the tag to determine parameters related to the transmission of the back scattering signal according to the first information, or the second information is used for indicating the tag to determine parameters related to the transmission of the back scattering signal according to a specific session number or process number.

In one embodiment of the application, the method further comprises:

the reader-writer transmits third information for instructing the tag to subtract the counter value by the third value.

In one embodiment of the application, the group identity or intra-group identity of the tag is determined according to one of the following: the first identifier; the first value; the second value; and information indicated by the reader-writer.

In one embodiment of the application, the method further comprises: the reader-writer transmits fourth information, the fourth information being used for indicating at least one of:

(1) Modifying the group identification of the tag;

(3) Modifying the intra-group identity of the tag;

(4) The tags identified within a particular group transmit backscatter signals.

In one embodiment of the present application, at least one of the first information, the second information, the third information, and the fourth information is carried by a control command;

In one embodiment of the present application, the reader/writer includes at least one of: the system comprises a terminal, a base station, a special receiving device and a special transmitting device.

In the embodiment of the application, the reader-writer determines the parameters related to the transmission of the back scattering signals according to the first information, and as the content contained in the first information is related to the tag itself or the content contained in the first information is a non-fixed value, the plurality of tags can adopt different parameters to transmit the back scattering signals at the same time, and further the reader-writer can detect the back scattering signals of the plurality of tags at the same time according to the parameters, so that the plurality of tags can be supported to perform back scattering transmission at the same time, and the efficiency of completing back scattering communication between the reader-writer and the tags is improved under the condition of a large number of tags.

The embodiment of the application is applicable to the scene comprising: the Tag communicates directly with the base station and the UE assists in the communication between the Tag and the base station.

Embodiments of the present application will be described below with reference to example one and example two.

Embodiment one: different tags use different parameters of the backscatter signal.

After receiving the control command of the reader-writer, the Tag can send the backscatter signal by using different parameters, that is, the reader-writer can instruct the Tag whether to adopt the first information or not to determine the parameters of the backscatter signal.

Different tags use different parameters of the backscatter signal in the following manner:

mode 1: the transmission of the backscatter signal occurs at a specific frequency.

For example, tag0 transmits a backscatter signal at frequency 0; tag1 transmits a backscatter signal at frequency 1; tag2 transmits the backscatter signal at frequency 2 so that a plurality of different Tags can transmit the backscatter signal at different frequencies at the same time.

Alternatively, the Tag generates backscatter signals of different frequencies by a local oscillator; or Tag generates backscatter signals of different frequencies by changing devices in the circuit, or parameters of the devices. Alternatively, the device may be a capacitor.

Mode 2: the information carried by the backscattered signal is modulated using different subcarriers (or subcarriers).

In existing backscatter communication systems, a backscatter signal is typically modulated by a subcarrier to modulate and backscatter transmit a useful signal, and one implementation is as follows:

each bit of information is modulated by a level switching of a plurality of periods, the switching of the level of each period T including at least two levels, for example, a high level and a low level corresponding to different reflection coefficients of the tag, the frequency of the subcarrier being fs=1/T. A manner of Miller (Miller) subcarrier modulation is shown in fig. 8.

The subcarrier is used to reflect the incoming carrier wave at a frequency Fc on the basis of the subcarrier modulated signal, so that the backscattered signal is modulated on the subcarriers of Fc + Fs and/or Fc-Fs.

For example, tag0 performs transmission of a backscatter signal on subcarrier 0; tag1 transmits a backscatter signal on subcarrier 1; tag2 transmits a backscatter signal on subcarrier 2; multiple tags may be transmitted back-scattered on different subcarriers at the same time instant. I.e. the signal of Tag0 after subcarrier modulation is at fc+fs0 and/or Fc-Fs0; signals of Tag1 after subcarrier modulation are in Fc+Fs1 and/or Fc-Fs1; signals of Tag2 after subcarrier modulation are in Fc+Fs2 and/or Fc-Fs2;

the Tag supports different subcarrier frequencies for backscatter transmission, and the first duration (or first level switching period) of the level is different for different subcarrier frequencies, but when any parameter of the backscatter signal is used for transmission of the backscatter signal, the second duration of the same bit number of transmission needs to be ensured to be the same.

As shown in fig. 8, when the Miller subcarrier modulation scheme is adopted, when the subcarrier frequency modulation scheme is adopted, the signal duration after the information symbol 0/1 modulation is the same. For example, when Tag#0 uses a subcarrier frequency of 640kHz and Tag#1 uses a subcarrier frequency of 320kHz, the level switching period and the electric frequency duration of Tag#0 are 1/2 of Tag#1. To ensure that Tag#0, tag#1 transmits the same number of information bits for the second duration. The switching cycle number M of the Tag #1 should also be 1/2 of the switching cycle number M of the Tag #0 in the duration of the modulated signal of one information bit, for example, the Tag #0 modulates the signal by using the modulation method of Miller 4 (switching frequency m=4), and the Tag #1 modulates the signal by using the modulation method of Miller 2 (m=2), so as to ensure that the second duration of the backscatter transmission of the same information bit number is the same when the backscatter transmission is performed by using different parameters, so as to ensure that the performance of the backscatter transmission is close when the backscatter transmission is performed by using different parameters.

Unlike the prior art, in RFID, miller 4, the transmission duration (second duration) after modulation of one information bit becomes longer than Miller 2, and the level switching period (or first duration) is the same. Thus Miller 4 has better transmission performance than Miller 2. In this embodiment, the level switching period (first duration) is different, and the transmission duration (second duration) after modulation of one information bit is the same.

In addition to modulation using Miller subcarriers (otherwise known as Miller code subcarriers), in a backscatter communication system, the backscattered information may be modulated to the subcarrier frequency using Manchester (Manchester) code, FM0 (i.e., bi-phase space code (Bi-Phase Space Coding)) code subcarriers.

Mode 3: the information carried by the backscattered signal is modulated with the duration of the different signal levels.

Mode 3 is similar to mode 2 in that T is changed by modifying the duration of a high/low level, thereby changing the frequency of the backscatter signal.

The parameters of the above-mentioned backscatter signal may be predefined or indicated by a reader.

Mode 4: the transmission of the backscatter signal occurs at a specific frequency.

In one implementation, the Tag may generate a transmit signal at one or more frequencies locally, reflecting the signal independent of the carrier. This type of Tag can be used for transmission of the backscatter signal at a specific frequency directly according to the control command of the reader, the indicated rule, or a predefined rule.

The following describes an implementation manner of receiving the backscatter signal at the reader/writer side in the first embodiment.

In the above-described modes 1, 2 and 3, the Tag can modulate the signal on the basis of the carrier signal with double sidebands, that is, generate a frequency component in the high-frequency direction and/or the low-frequency direction of the carrier frequency, respectively. Or single sideband modulation, for example using the method of mode 4, generates frequency components only in the high or low frequency direction of the carrier frequency. The frequency components above or below the carrier frequency contain back-scattered modulated information. The reader may use a filter to filter out certain frequency components to detect the information transmitted by the backscattered signal.

The reader-writer can take out signals with different frequencies through a filter to demodulate, so as to obtain signals transmitted by different tags through back scattering, and the components of the back scattering signals in frequency are shown in fig. 9.

Embodiment two: rules for determining backscatter parameters

In existing backscatter communication systems, a reader-writer typically receives only one Tag's backscatter signal at a time. For example, in the RFID inventory process, when the reader sends a control command to start the inventory process, a value Q is indicated. Tag randomly selects a value q among the values that locally generate a {0, …,2^Q-1 }. The Tag with the current random value of 0 responds to the control command of the reader to transmit the backscatter signal. The transmission of the backscatter signal is temporarily not performed by the Tag whose current random value is not 0. After completing communication with a Tag having a random value of 0, the reader/writer may continue to transmit a control command (e.g., queryRep) indicating, for example, that the Tag subtracts 1 from the generated random number, and that the Tag having a random value of 0 performs transmission of a backscatter signal in response to the control command.

The above procedure belongs to the random multiple access procedure, and there is a possibility that multiple tags locally generate the same random number, so that multiple tags may perform backscatter transmission at the same time. In this case, the tags will continue to receive the control commands from the reader/writer, waiting for a new opportunity for backscatter transmission. Therefore, when the reader-writer sends a control command, a reasonable Q value is selected, and the Q value can be gradually adjusted in the checking process so as to reduce the collision probability in the communication process with a plurality of tags. When this is allowed to mean also a prolonged time to complete a communication with a plurality of tags.

In the existing scheme design, if the parameters of the backscattering signal transmission of a plurality of tags at the same time are the same, the reader-writer side cannot detect the backscattering signals of the plurality of tags at the same time, and the efficiency of completing the backscattering communication of the plurality of tags is negatively affected.

Based on the method for transmitting a backscatter signal in the first embodiment, transmission of the backscatter signal can be performed at the same time using different parameters. Thus, the efficiency of the multi-Tag communication flow can be improved. For example, frequency shifting of the incoming signal is achieved by means of hardware, or different backscatter signals of different tags are achieved at different target frequencies by different subcarrier modulation/level durations.

The way the Tag determines the parameters of the different backscatter signals includes determining the parameters of the backscatter signal (or determining the parameters for backscatter transmission) from the counter value of the Tag, such as:

mode a: a parameter of the backscatter signal is determined based on the step size.

The tags with the current counter values of 0,1 and … M-1 can simultaneously carry out backscatter transmission, and the tags with different counter values use different parameters for backscatter transmission. Tag0 uses parameter 0, tag1 uses parameter 1, …, tag M uses parameter M for backscatter transmission, 0= < M < = M-1. The counter value may be a random number generated locally by the Tag, or a counter value obtained by modification (decrementing/incrementing) of the random number.

Alternatively, tags of different IDs are backscatter transmitted using different parameters, tag id#0 using parameter 0, tag id#1 using parameter 1, …, tag id#m using parameter M, 0= < M < = M-1. The ID is a temporary ID of the UE, the reader indicates the ID, the article codes PC and the electronic article codes EPC. The Tag can determine the parameters of the backscatter signal from the output of the ID value after a certain operation, for example, if mod (ID, M) =m, the parameter M is used for backscatter transmission.

In the above implementation manner, the reader/writer may indicate the step size of the random number adjustment in the control command, for example, the above M may be regarded as the step size of the random number adjustment, and if the Tag receives the control command indicated by the reader/writer and indicates that the step size of the adjustment M >1, the Tag determines the parameter of the Tag for performing the backscatter signal in the above manner.

Mode b: the parameters of the backscatter signal are determined based on the group ID or the intra-group ID.

The Tag may operate in a packet mode, and the Tag contains a group ID, an intra-group ID. The parameters of the backscatter signal are determined from the intra-group ID.

One implementation is to transmit a backscatter signal for a Tag of a particular group ID, and determine parameters of the backscatter signal, such as frequency, subcarrier frequency, first level duration/first level switching period, based on the Tag group ID.

For example, tag#0 uses parameter 0, tag#1 uses parameter 1 … …, and multiple Tags use different parameters for backscatter transmission simultaneously. The reader/writer may further modify the group ID of the Tag by a control command, e.g., one or more tags with a group ID of 0 will not perform backscatter transmission. After the transmission of the backscatter signal by one or more tags with a group ID of 0, the reader/writer may instruct the modification of the value of the group ID, for example the group ID minus 1, by a control command. At this time, the Tag with the previous group ID of 1, the group ID of 0, and the Tag in the reorganization transmit the backscatter signal (or simply referred to as backscatter transmission).

In another implementation, the transmission of the backscatter signal is performed for the Tag of the particular group ID, and parameters of the backscatter signal, such as frequency, subcarrier frequency, first level duration/first level switching period, are determined based on the Tag group ID.

For example, the Tag group (Tag group) #0 uses the parameter 0, the Tag roup#1 uses the parameter 1 … …, and a plurality of tags use different parameters for simultaneous backscatter transmission. The reader may further modify the intra-group ID of the Tag by a control command, e.g., one or more tags with an intra-group ID of 0 will not undergo backscatter transmission. After one or more tags with a 0 in the group ID have been back-scattered, the reader/writer may indicate by a control command to modify the value of the in-group ID, e.g., the in-group ID minus 1. At this time, the Tag with the ID of 1 in the previous group has the ID of 0 in the previous group, and the tags with the IDs of 0 in the plurality of groups perform backscatter transmission.

The group ID or intra-group ID of the Tag in the present embodiment may be determined for one of the following: according to the Tag (represented by A) or temporary Tag (represented by B), the random number generated by Tag (represented by C), the counter value of Tag (represented by D), and the information indicated by the reader;

mode c: the parameters of the backscatter signal are determined from simple operations of the Tag's identity (a), or the temporary identity (B), the Tag-generated random number (C) or the Tag's counter value (D).

For example, the parameters of the backscatter signal are determined from the value of m=mod (a/B/C/D, M); m is indicated by the reader or predefined. The Tag uses the parameter m for transmission of the backscatter signal.

Mode d: and determining whether to adopt a working mode of parallel backscattering of a plurality of tags based on the process number or the session number.

The reader may communicate with multiple tags using multiple sessions or processes for different purposes.

For example, the reader/writer needs to communicate with a plurality of tags, for example, inventory (inventory) of tags. For session-specific or process-specific communications, backscatter transmission is performed in the manner described above. The specific session number (session number), or process number (process number) may be predefined, or indicated by a reader/writer.

Embodiment III: signaling indication

Optionally, the related indication signaling is indicated by the reader/writer, and the related information may be indicated in a control command, where the control command is used to select a Tag that partially meets the condition or all tags open a communication flow. Or may be changed when the control command indicates the Q value used to generate the random number. Along with these parameters, the relevant parameters required for the procedure are indicated, for example a step value M indicating a random number adjustment. Or use these commands to indicate whether the Tag is to use the above mode for backscatter communications.

Optionally, the parameter of the backscatter signal may also be indicated by the control command described above, including at least one of:

a) Different frequency offset values are carried out relative to the incident carrier signal, and the frequency offset values are predefined or indicated by a reader;

b) N times or 1/N relative to the reference subcarrier frequency;

c) K times or 1/K relative to the reference level duration.

Referring to fig. 10, an embodiment of the present application provides a backscatter signal transmission device for application to a tag, the device 1000 comprising:

a first determining module 1001, configured to determine a parameter related to transmission of a backscatter signal according to the first information;

Wherein the first information includes at least one of:

(2) A first value indicating a random number generated by the tag;

(3) A second value for indicating a counter value of the tag;

(4) A third value for indicating a step size of a counter of the tag;

(5) A group identification or an intra-group identification of the tag;

(6) Session number (session number) or process number (process number);

(7) Information received from the reader/writer;

wherein the parameters of the backscatter signal include at least one of:

(1) A parameter of the backscatter signal, the parameter of the backscatter signal being indicative of transmission of the backscatter signal;

(3) A third parameter indicative of a frequency of the backscattered signal;

(4) A subcarrier (subcarrier) frequency of the backscattered signal;

subcarriers may also be described herein as subcarriers.

In one embodiment of the present application, the third parameter is a first frequency offset value, the first frequency offset value being used to indicate a frequency offset value relative to an incident carrier frequency; alternatively, the subcarrier frequency of the backscattered signal is N times or 1/N times the reference subcarrier frequency; alternatively, the first duration is K times or 1/K times the reference level duration;

wherein N, K is a natural number greater than 0.

In one embodiment of the application, one or more of the incident carrier frequency, the reference subcarrier frequency, the reference level duration, the first frequency offset value, the N and the K are predefined or indicated by a reader.

In one embodiment of the application, the apparatus further comprises:

the first receiving module is configured to receive second information, where the second information is used to instruct the tag to determine a parameter related to the transmission of the backscatter signal according to the first information, or the second information is used to instruct the tag to determine a parameter related to the transmission of the backscatter signal according to a specific session number or a process number.

In one embodiment of the present application, the first determining module 1001 is further configured to:

And in the case that the third value is included in the first information and the third value is greater than 1, determining a parameter related to the transmission of the backscatter signal according to the first information.

In one embodiment of the application, the apparatus further comprises:

and the first transmission module is used for transmitting a back scattering signal when the counter value of the tag is any one of 0 to a fourth value, the fourth value is equal to the third value minus 1, and the third value is greater than or equal to 1.

In one embodiment of the application, the apparatus further comprises:

and the second receiving module is used for receiving third information, and the third information is used for indicating the tag to subtract the third value from the counter value.

determining the parameter according to the group identifier of the tag under the condition that the group identifier of the tag is a specific group identifier; or in the case that the group identifier of the tag is a specific group identifier, determining the parameter according to the group identifier of the tag.

In one embodiment of the application, the group identity or intra-group identity of the tag is determined according to one of the following: the first identifier; the first value; the second value; information indicated by the reader/writer.

a remainder obtained by dividing the first identifier or the first value or the second value by the fifth value is determined as the parameter; wherein the fifth value is indicated by the reader or predefined.

In one embodiment of the present application, the apparatus further comprises: a third receiving module, configured to receive fourth information, where the fourth information is used to indicate at least one of the following:

modifying the group identification of the tag;

the tag of the specific group identifier transmits a back scattering signal;

modifying the intra-group identity of the tag;

the tags identified within a particular group transmit backscatter signals.

In one embodiment of the application, the apparatus further comprises:

a third transmission module, configured to transmit a backscatter signal according to the first requirement and a parameter of the backscatter signal;

Referring to fig. 11, an embodiment of the present application provides a backscatter signal transmission device, applied to a reader/writer, the device 1100 includes:

A third determining module 1101 for determining a parameter related to the transmission of the backscatter signal based on the first information;

a detection module 1102, configured to detect the backscatter signal according to the parameter;

wherein the first information includes at least one of:

(2) A first value indicating a random number generated by the tag;

(3) A second value for indicating a counter value of the tag;

(4) A third value for indicating a step size of a counter of the tag;

(5) A group identification or an intra-group identification of the tag;

(6) Session number (session number) or process number (process number);

(7) Information received from the reader/writer.

In one embodiment of the application, the parameter of the backscatter signal comprises at least one of:

(3) A third parameter indicative of a frequency of the backscattered signal;

(4) A subcarrier (subcarrier) frequency of the backscattered signal;

subcarriers may also be described herein as subcarriers.

or,

the first duration is K times or 1/K times the reference level duration;

wherein N, K is a natural number greater than 0.

In one embodiment of the application, the apparatus further comprises:

the first sending module is used for sending second information, the second information is used for indicating the tag to determine parameters related to the transmission of the back scattering signal according to the first information, or the second information is used for indicating the tag to determine parameters related to the transmission of the back scattering signal according to a specific session number or process number.

In one embodiment of the application, the apparatus further comprises:

and the second sending module is used for sending third information, and the third information is used for indicating the tag to subtract the third value from the counter value.

In one embodiment of the application, the apparatus further comprises:

a third sending module, configured to send fourth information, where the fourth information is used to indicate at least one of the following:

modifying the group identification of the tag;

the tag of the specific group identifier transmits a back scattering signal;

Modifying the intra-group identity of the tag;

the tags identified within a particular group transmit backscatter signals.

In one embodiment of the present application, the reader/writer includes a terminal, a base station, a dedicated receiving device, or a dedicated transmitting device.

The device provided by the embodiment of the application can realize each process realized by the embodiment of the method of fig. 7 and achieve the same technical effect, and in order to avoid repetition, the description is omitted here.

Optionally, as shown in fig. 11, the embodiment of the present application further provides a communication device 1100, including a processor 1101 and a memory 1102, where the memory 1102 stores a program or instructions that can be executed on the processor 1101, for example, when the communication device 1100 is a terminal, the program or instructions implement each step of the method embodiment of fig. 5 or fig. 6 when executed by the processor 1101, and the same technical effects can be achieved, so that repetition is avoided and no further description is provided herein.

The embodiment of the present application further provides a readable storage medium, where a program or an instruction is stored, where the program or the instruction implements the method of fig. 5 or fig. 6 and the processes of the foregoing embodiments when executed by a processor, and the same technical effects can be achieved, so that repetition is avoided, and no further description is given here.

Wherein the processor is a processor in the terminal described in the above embodiment. The readable storage medium includes computer readable storage medium such as computer readable memory ROM, random access memory RAM, magnetic or optical disk, etc.

The embodiment of the application further provides a chip, the chip includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used for running a program or instructions, implementing each process of each method embodiment shown in fig. 5 or fig. 6 and described above, and achieving the same technical effect, so that repetition is avoided, and no further description is provided here.

It should be understood that the chips referred to in the embodiments of the present application may also be referred to as system-on-chip chips, or the like.

The embodiments of the present application further provide a computer program/program product stored in a storage medium, where the computer program/program product is executed by at least one processor to implement the processes shown in fig. 2 or fig. 3 and described above in the embodiments of the methods, and achieve the same technical effects, so that repetition is avoided and detailed description is omitted herein.

The embodiment of the present application further provides a communication system, where the communication system includes a terminal and a network side device, the terminal is configured to execute each process of the embodiments of the method as shown in fig. 5 and described above, and the network side device is configured to execute each process of the embodiments of the method as shown in fig. 6 and described above, and the same technical effects can be achieved, so that repetition is avoided, and no further description is given here.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of the present application is not limited to performing the functions in the order shown or discussed, but may also include performing the functions in a substantially simultaneous manner or in an opposite order depending on the functions involved, e.g., the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a computer software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) comprising instructions for causing a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the method according to the embodiments of the present application.

The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are to be protected by the present application.

Claims

1. A method of backscatter signal transmission, comprising:

wherein the first information includes at least one of:

a first value indicating a random number generated by the tag;

a second value for indicating a counter value of the tag;

a third value for indicating a step size of a counter of the tag;

a group identification or an intra-group identification of the tag;

session number or process number;

information received from the reader/writer.

2. The method of claim 1, wherein the parameters include at least one of:

a first parameter indicative of transmission of a backscatter signal;

a second parameter indicating that transmission of the backscatter signal is not to be performed;

a third parameter indicative of a frequency of the backscattered signal;

subcarrier frequencies of the backscattered signals;

a first duration or a first level switching period of the backscatter signal.

3. The method of claim 2, wherein the third parameter is a first frequency offset value, the first frequency offset value being indicative of a frequency offset value relative to an incident carrier frequency;

or,

the first duration is K times or 1/K times the reference level duration;

wherein, N and K are natural numbers greater than 0.

4. A method according to claim 3, wherein one or more of the incident carrier frequency, the reference subcarrier frequency, the reference level duration, the first frequency offset value, the N and the K are predefined or indicated by a reader.

5. The method according to claim 1, wherein the method further comprises:

the tag receives the second information and,

the second information is used for indicating the tag to determine the parameters related to the transmission of the back-scattered signal according to the first information, or the second information is used for indicating the tag to determine the parameters related to the transmission of the back-scattered signal according to a specific session number or process number.

6. The method of claim 1, wherein the tag determines a parameter of the backscatter signal based on the first information, comprising:

7. The method of claim 6, wherein the method further comprises:

8. The method of claim 6, wherein the method further comprises:

the tag receives third information indicating that the tag subtracts the third value from the counter value.

9. The method of claim 1, wherein the tag determining parameters associated with the transmission of the backscatter signal based on the first information, comprising:

in the case that the group identifier of the tag is a specific group identifier, the tag determines the parameter according to the group identifier of the tag;

Or,

and in the case that the group identifier of the tag is a specific group identifier, the tag determines the parameter according to the group identifier of the tag.

10. The method according to claim 1 or 9, wherein the group identity or intra-group identity of the tag is determined according to one of the following: the first identifier; the first value; the second value; information indicated by the reader/writer.

11. The method of claim 10, wherein the tag determining the parameter based on a group identification or an intra-group identification of the tag comprises:

the tag determines the remainder obtained by dividing the first identifier or the first value or the second value by the fifth value as the parameter;

wherein the fifth value is indicated by the reader or predefined.

12. The method according to claim 10, wherein the method further comprises:

modifying the group identification of the tag;

the tag of the specific group identifier transmits a back scattering signal;

modifying the intra-group identity of the tag;

the tags identified within a particular group transmit backscatter signals.

13. The method of claim 1, 5, 8 or 12, wherein at least one of the first information, the second information, the third information, the fourth information is carried in a control command sent by a reader/writer;

14. The method according to claim 1, wherein the method further comprises:

15. The method of claim 14, wherein the step of providing the first information comprises,

and in the second duration, the level switching cycle number corresponding to the subcarrier frequency of the backscatter transmission is 1/N of the level switching cycle number corresponding to the reference subcarrier frequency when the subcarrier frequency of the backscatter signal is N times the reference subcarrier frequency.

16. The method of claim 15, wherein the level switching cycle comprises, in order: high level and low level, or low level and high level, wherein the sum of the duration of the high level and the duration of the low level is the level switching period.

17. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, 15, or 16, wherein the information carried by the backscattered signal comprises at least one of: the temporary identification of the tag, the article coding, the handle of the tag, the error coding and the data.

18. A method of backscatter signal transmission, comprising:

the reader detects the backscatter signal according to the parameter;

wherein the first information includes at least one of:

a first value indicating a random number generated by the tag;

a second value for indicating a counter value of the tag;

A third value for indicating a step size of a counter of the tag;

a group identification or an intra-group identification of the tag;

session number or process number;

information received from the reader/writer.

19. The method of claim 18, wherein the parameters include at least one of:

a first parameter indicative of transmission of a backscatter signal;

a third parameter indicative of a frequency of the backscattered signal;

subcarrier frequencies of the backscattered signals;

a first duration or a first level switching period of the backscatter signal.

20. The method of claim 18, wherein the reader/writer performing detection of the backscatter signal based on the parameter comprises:

21. The method of claim 19, wherein the third parameter is a first frequency offset value, the first frequency offset value being indicative of a frequency offset value relative to an incident carrier frequency;

Or,

or,

the first duration is K times or 1/K times the reference level duration;

wherein, N and K are natural numbers greater than 0.

22. The method of claim 21, wherein one or more of the incident carrier frequency, the reference subcarrier frequency, the reference level duration, the first frequency offset value, the N, and the K are predefined or determined by the reader.

23. The method of claim 18, wherein the method further comprises:

24. The method of claim 18, wherein the method further comprises:

25. The method of claim 18, wherein the group identification or intra-group identification of the tag is determined according to one of: the first identifier; the first value; the second value; and information indicated by the reader-writer.

26. The method of claim 18, wherein the method further comprises:

the reader-writer transmits fourth information, the fourth information being used for indicating at least one of:

modifying the group identification of the tag;

the tag of the specific group identifier transmits a back scattering signal;

modifying the intra-group identity of the tag;

the tags identified within a particular group transmit backscatter signals.

27. The method of claim 18, 23, 24 or 26, wherein at least one of the first information, the second information, the third information, the fourth information is carried by a control command;

28. The method of any one of claims 18 to 26, wherein the reader/writer comprises at least one of: the system comprises a terminal, a base station, a special receiving device and a special transmitting device.

29. A backscatter signal transmission device comprising:

wherein the first information includes at least one of:

a first value indicating a random number generated by the tag;

a second value for indicating a counter value of the tag;

a third value for indicating a step size of a counter of the tag;

a group identification or an intra-group identification of the tag;

session number or process number;

information received from the reader/writer.

30. The apparatus of claim 29, wherein the parameters comprise at least one of:

a first parameter indicative of transmission of a backscatter signal;

a third parameter indicative of a frequency of the backscattered signal;

subcarrier frequencies of the backscattered signals;

A first duration or a first level switching period of the backscatter signal.

31. The apparatus of claim 29, wherein the apparatus further comprises:

32. The apparatus of claim 29, wherein the first determination module is further configured to:

33. The apparatus of claim 29, wherein the apparatus further comprises:

a third receiving module, configured to receive fourth information, where the fourth information is used to indicate at least one of the following:

modifying the group identification of the tag;

The tag of the specific group identifier transmits a back scattering signal;

modifying the intra-group identity of the tag;

the tags identified within a particular group transmit backscatter signals.

34. A backscatter signal transmission device for use with a reader/writer, comprising:

a first value indicating a random number generated by the tag;

a second value for indicating a counter value of the tag;

a third value for indicating a step size of a counter of the tag;

a group identification or an intra-group identification of the tag;

session number or process number;

information received from the reader/writer.

35. The apparatus of claim 34, wherein the parameters comprise at least one of:

a first parameter indicative of transmission of a backscatter signal;

a third parameter indicative of a frequency of the backscattered signal;

subcarrier frequencies of the backscattered signals;

a first duration or a first level switching period of the backscatter signal.

36. The apparatus of claim 34, wherein the apparatus further comprises:

37. The apparatus of claim 34, wherein the apparatus further comprises:

modifying the group identification of the tag;

the tag of the specific group identifier transmits a back scattering signal;

modifying the intra-group identity of the tag;

the tags identified within a particular group transmit backscatter signals.

38. A communication device comprising a processor, a memory and a program or instruction stored on the memory and executable on the processor, which when executed by the processor implements the steps of the method of any of claims 1 to 28.

39. A readable storage medium, characterized in that it has stored thereon a program or instructions which, when executed by a processor, implement the steps of the method according to any of claims 1 to 28.